The human prostate is the most commonly diseased of all internal organs with the highest frequency of cancer and of benign hyperplasia. Prostatic carcinoma is found in 50% or more of elderly men examined by autopsy. Several variables in the occurrence and natural history of prostate cancer make it especially difficult to treat. Statistics indicate that less than 1% of prostate cancers cause clinical disease. Yet when they do, 50% of the patients present with metastases, and their average survival time is less than two years. Clinical management of this disease is further complicated by the fact that localized prostatic cancers of the same histologic grade do not always behave uniformly. An understanding of the cellular bioenergetics of this cancer may help in understanding and perhaps predicting its biologic behavior. The objective of this study is to assess the clinical role of 3-dimensional MR citrate metabolite imaging for providing a noninvasive measure of prostatic function. Citrate production and excretion is a unique and major function of the secretory epithelial cells of the prostate gland. Preliminary data demonstrate that citrate levels are greatly reduced in prostatic adenocarcinoma as compared to normal prostatic tissue and benign prostatic hyperplasia (BPH). Presently there is no noninvasive technique to differentiate between these tissues. In order to fulfill this need, we have recently developed acquisition and analysis procedures to obtain 3-D water- and fat- suppressed 1H spectroscopic images of the citrate distributions throughout the in situ human prostate at a spatial resolution of 0.5-l cc. If this method could differentiate between BPH and cancer, it could significantly impact clinical management of these diseases. In this project we will also introduce a method for field-correcting transrectal citrate and proton MR images which provides high resolution images of the prostate corrected for the intensity distortions due to the reception profile of the endorectal coil. We will apply these novel techniques to a specific population of patients prior to surgery (radical or simple prostatectomy) to allow direct correlations of citrate levels to biopsy data, transrectal ultrasound data, histopathological and biochemical analysis of surgically-excised tissue. We aim to determine whether the functional information which. MR citrate imaging provides could be used as a noninvasive indicator of the presence, degree, and extent of prostatic malignancy and benign hyperplasia and their response to therapy.